1. Field of the Invention
The present invention concerns a method of manufacturing a frequency adapter. A frequency adapter is a device which filters and damps vibration. The frequency adapter is inserted between two parts one of which is subject to or the source of vibrations.
2. Description of the Prior Art
The invention applies to a frequency adapter of the cylindrical kind comprising at least one assembly formed by an elastomer ring molded between an inner armature and a cylindrical ring, said elastomer ring adhering to the armature and to the cylindrical ring, said assembly or assemblies being sleeved into an external sheath.
If the adapter comprises a single such assembly one of the parts between which it is inserted is fixed to the inner armature and the other to the outer sheath. However, the adapter may comprise two aligned assemblies and in this case one of the parts is fixed to the inner armature of one assembly and the other to the inner armature of the other assembly. The outer sheath is then used to join the two assemblies together.
When an assembly of this kind cools after the elastomer ring is molded the resulting shrinkage causes residual stresses in the elastomer ring. These stresses must be eliminated to prevent breakdown of adhesion and because they reduce the service life of the adapter because of increased fatigue. A known way to eliminate these stresses is to reduce the diameter of the component using a known tool. This operation involves deformation beyond the elastic limit, i.e. plastic deformation. However, during this operation the cylindrical ring whose diameter is reduced is deformed and is no longer perfectly circular. It is therefore necessary to machine the assembly after the reduction in diameter in order to make it circular and to achieve the required final dimension before it is sleeved into the outer sheath.
An object of the present invention is to avoid such machining and to simplify the operation of sleeving the assembly into the outer sheath.